JPH06273511A - Gps receiver for survey - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a GPS receiver for surveying that can achieve improved accuracy, lighter weight, and lower cost. [Configuration] The first GPS receiver 10 includes a GPS antenna 2
2, an analog signal processing unit 34 for converting the radio wave received by the satellite S into a frequency lower than that of the radio wave emitted from the satellite S, and a radio for transmitting a radio signal from the transmission antenna 28 upon receiving an output signal of the analog signal processing unit 34. And a signal transmission unit 36. The other second GPS receiver includes a wireless signal receiving unit having a receiving antenna for receiving the wireless signal, and G
An analog signal processing unit that frequency-amplifies and amplifies the radio wave received by the PS antenna, and a digital that generates phase data by digitizing the carrier wave phase of the radio wave from the output signals of the radio signal receiving unit and the analog signal processing unit. And a signal processing unit. In the present invention, the phase data is generated from the radio waves received by the two receivers 10 by one digital signal processing unit, so that the sampling periods can be completely matched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a GPS receiver used for static surveys and kinematic surveys.

[0002]

2. Description of the Related Art A survey using a GPS system is known. In this type of survey, radio waves transmitted from a plurality of (four or more) satellites are received by a plurality of GPS receivers at the same time, By calculating the phase difference of the radio waves received between the GPS receivers, the distance and direction between points on the earth are measured. In surveys using such a GPS system, GPS receivers are installed at two points, a known point and an unknown point, and two receivers receive radio waves from satellites at the same time. A method called kinematic surveying is known in which a receiver is fixedly installed at a known point, and the other GPS receiver is sequentially moved to a measurement point for measurement.

By the way, G used for such surveying
PS receivers generally correspond to the number of satellites, a GPS antenna that receives radio waves transmitted from satellites, an analog signal processing unit that frequency-converts and amplifies the radio waves received by the GPS antennas. A digital signal processing unit having a number of channels, which generates phase data by digitizing the carrier wave phase of the radio wave from the output signal of the analog signal processing unit for each channel, and the satellite for each channel of the digital signal processing unit. The digital signal processing unit has a control unit that specifies the phase data sent from the digital signal processing unit at predetermined time intervals and stores the extracted phase data in the storage unit as epoch phase data. Being prepared.

However, such a conventional GPS receiver has the technical problems described below.

[0005]

That is, the conventional GPS receiver described above requires at least two receivers each having a signal processing unit and a control unit having exactly the same configuration. In particular, a digital signal handling a digital signal is required. The processing unit and the control unit are relatively expensive, which has been a major cause of increasing the price of the surveying receiver. Further, since the signal is received by at least two receivers, the phase data is generated from the radio wave received from the satellite by the digital signal processing unit of each receiver, so that there is a problem that the sampling cycle of the phase data is shifted.

Further, particularly in kinematic surveying, the receiver has to carry one receiver on one's back and must move to a plurality of measurement points, and therefore, it has been required to reduce the weight of the GPS receiver. However, it has not been possible to sufficiently meet this demand by downsizing electronic components used. The present invention has been made in view of the above problems, and an object thereof is to improve the accuracy of surveying by completely matching the sampling periods of the phase data, and to reduce the weight. It is an object of the present invention to provide a GPS receiver for surveying that can achieve cost reduction at the same time.

[0007]

To achieve the above object, the present invention uses at least a pair of GPS receivers that receive radio waves transmitted from a plurality of satellites, and installs the GPS receivers at different points. Then, in the surveying GPS receiver that measures the distance and direction between the points based on the phase of the received radio waves received at the same time by the GPS receiver, one of the GPS receivers is A GPS antenna that receives radio waves transmitted from satellites and this GP
An analog signal processing unit for converting a radio wave received by the S antenna into a carrier frequency lower than that of the radio wave emitted from the satellite, and a radio for transmitting a radio signal from a transmission antenna upon receiving an output signal of the analog signal processing unit. The other of the GPS receivers has a radio signal reception unit having a signal transmission unit and a reception antenna for receiving the radio signal, a GPS antenna for receiving radio waves transmitted from the satellite, and the GPS antenna. An analog signal processing unit that frequency-amplifies and amplifies the radio wave received by the digital signal processing unit that generates phase data by digitizing the carrier wave phase of the radio wave from the output signals of the radio signal receiving unit and the analog signal processing unit. Section and the phase data sent from the digital signal processing section at predetermined time intervals and stored in the storage means as epoch phase data. And a control unit for 憶, the digital signal processing unit is characterized by having a plurality of channels, wherein the phase data corresponding to the analog signal processing unit and the radio signal reception section is assigned, respectively.

[0008]

According to the surveying GPS receiver having the above structure, one of the GPS receivers has an analog signal processing unit for converting the radio wave received by the GPS antenna into a carrier frequency lower than the radio wave emitted from the satellite. A radio signal transmitting section for transmitting a radio signal from a transmitting antenna in response to the output signal of the analog signal processing section, and a radio signal receiving section having a receiving antenna for receiving the radio signal in the other GPS receiver; , An analog signal processing unit that frequency-converts and amplifies a radio wave received by a GPS antenna, and generates phase data by digitizing a carrier wave phase of the radio wave from output signals of the radio signal receiving unit and the analog signal processing unit. Since the digital signal processing unit is provided, the phase data can be generated by one digital signal processing unit from the radio waves received by the two GPS receivers. To become, thereby exact match of the sampling period.

Further, one of the receivers has a conventional digital signal processing section and a control section which are removed and a radio signal transmitting section having an antenna is provided instead of them, so that the weight and cost can be reduced. Can be achieved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. 1 to 5 show an embodiment of a GPS receiver for surveying according to the present invention. The GPS receiver shown in the figure has first and second GPS receivers 10, 12 at an unknown point A and a known point B on the earth, respectively.
Is installed to transmit radio waves transmitted from at least four satellites S (S _{1 to} S ₄ ) to the first and second GPS receivers 10 and 1.
2 received at point A based on the phase difference of the received radio waves,
The case where the present invention is applied to a static survey for obtaining the distance X between B is illustrated.

First GPS receiver 1 installed at unknown point A
Details of 0 are shown in FIGS. First GP shown in FIG.
The S receiver 10 employs a form supported by a pole 14, and a power battery 20 and a GPS antenna 22 composed of a microstrip in a hemispherical cover 18 having a power switch 16 on the outer surface. A printed circuit board 24 on which electronic components such as an amplifier are mounted is housed. The support form of the first GPS receiver 10 is not limited to that shown in the figure, and may be a form of being mounted on the top of three legs, for example.

An antenna holder 26 is mounted on the outer periphery of the pole 14, and a rod-shaped wireless transmission antenna 28 is supported by the antenna holder 26. The transmitting antenna 28 is connected to the printed circuit board 24 by a cable 32 via a connector 30 attached to the lower surface of the cover 18.
It is connected to the. FIG. 3 is a block diagram showing an electrical configuration of the first GPS receiver 10. The first GPS receiver 10 is connected to the GPS antenna 22, and the radio waves from the satellite S received by the GPS antenna 22 are The carrier frequency f _{1 of the} radio wave transmitted from the satellite S, for example, this is L
If it is _one signal, it becomes 1575.42 MHz, and a carrier frequency f ₂ lower than this, for example, an analog signal processing unit 34 for converting to 63 MHz, and this analog signal processing unit 3
4 and a radio signal transmitting unit 36 for transmitting a radio signal from the transmitting antenna 28.

The analog signal processing section 34 of the first GPS receiver 10 includes a low noise amplifier 34a connected to the GPS antenna 22, a first bandpass filter 34b connected to the output side of the amplifier 34a, and a local oscillator 34c. When,
The output signal of the bandpass filter 34b and the local oscillator 34
It has a mixer 34d for mixing the output signal of c and converting it to a predetermined carrier frequency, and a second bandpass filter 34e connected to the output side of the mixer 34d.

The radio signal transmitting section 36 has an intermediate frequency amplifier 36a connected to the output side of the second band pass filter 34e of the analog signal processing section 34, and power connected to the output side of the intermediate frequency amplifier 36a. The amplifier 36b is included, and the transmitting antenna 28 is connected to the output side of the power amplifier 36b. Second G installed at known point B
Details of the PS receiver 12 are shown in FIGS. The second GPS receiver 12 shown in the figure has a GPS antenna 42 which is housed in a hemispherical cover 40 supported by a tripod 38 and which receives radio waves transmitted from the satellite S. Further, in the cover 40, a printed circuit board 46 on which electronic components forming an analog signal processing section 44 for frequency-converting and amplifying a carrier frequency of a radio wave received by the GPS antenna 42 are mounted is housed.

The analog signal processing unit 44 is connected to a receiver main body 52 via a connector 48 attached to the cover 40 and a cable 50, and inside the receiver main body 52,
The wireless signal receiving unit 54, the digital signal processing unit 56, the control unit 58, and the memory 60 are housed, the operation unit and the display unit are provided on the front side, and the wireless signal receiving unit 54 and the electric unit are provided on the back side. A reception antenna 62 that is electrically connected is attached.

FIG. 5 is a block diagram showing the electrical construction of the second GPS receiver 12. The analog signal processing unit 44 of the second GPS receiver 12 includes a low noise amplifier 44a connected to the GPS antenna 42, a first band pass filter 44b connected to the output side of the amplifier 44a, a local oscillator 44c, and a band. by mixing the output signal of the output signal and the local oscillator 44c of the pass filter 44b, a mixer 44d for converting into a predetermined carrier frequency f _3, the mixer 44d
Second bandpass filter 44e connected to the output side of
And an intermediate frequency amplifier 44f connected to the output side of the second bandpass filter 44e.

Further, the radio signal receiving section 54 has a low noise amplifier 54a connected to the receiving antenna 62 and the first bandpass filter 5 connected to the output side of the amplifier 54a.
4b, a local oscillator 54c, and a bandpass filter 54
by mixing the output signal of b and the output signal from the local oscillator 54c, a mixer 54d for converting into a predetermined carrier frequency f _4,
It has a second bandpass filter 54e connected to the output side of the mixer 54d and an intermediate frequency amplifier 54f connected to the output side of the second bandpass filter 54e.

The digital signal processing unit 56 generates phase data by digitizing the carrier wave phase of the radio wave from the output signals of the radio signal receiving unit 54 and the analog signal processing unit 44. S. P (Digital Signal
Be composed of Processor), it has at least 8 more than the number of channels, in this embodiment, electric waves received directly from the satellite S ₁ to S ₄ 1 to 4 channels at the 2GPS receiver 12, i.e., an analog signal The remaining 5 to 8 channels are assigned to the signals output from the processing unit 44, and the remaining 5 to 8 channels are assigned to the radio waves received from the satellites S _{1 to} S _{4 by the first} GPS receiver 10, that is, the signals output from the wireless signal receiving unit 54. To be

The control unit 58 extracts the phase data sent from the digital signal processing unit 56 at predetermined time intervals and stores it in the memory 60 as epoch phase data. Specifically, it is from a microcomputer. Configured, the memory 60 may be either an internal memory or an external memory, eg, a memory card. In the GPS receiver configured as described above, the first GPS receiver 10 is installed at the unknown point A, the second GPS receiver 12 is installed at the known point B, and the same time is transmitted from the plurality of satellites S _{1 to} S _4. To the distance X between points A and B from the phase difference of the carrier wave
Will be asked. In this case, the first GPS receiver 10
The carrier frequency f ₂ that is frequency-converted by the analog signal processing unit 34 of the
If the carrier frequency f ₃ to be frequency-converted in 4 is matched, the frequency-converting portion in the configuration of the radio signal receiving section 54 of the second GPS receiver 12 becomes unnecessary, and the configuration can be further simplified.

Now, the surveying GP constructed as described above
In the S receiver, the first GPS receiver 10 includes an analog signal processing unit 34 that converts a radio wave received by the GPS antenna 22 into a lower frequency than a radio wave emitted from the satellite S.
A radio signal transmission unit 36 that receives the output signal of the analog signal processing unit 34 and transmits a radio signal from the transmission antenna 28.
And the other second GPS receiver 12 has a radio signal receiving section 54 having a receiving antenna 62 for receiving the radio signal, and an analog signal processing for frequency-converting and amplifying the radio wave received by the GPS antenna 42. Since the unit 44 and the digital signal processing unit 56 that generates phase data by digitizing the carrier wave phase of the radio wave from the output signals of the radio signal receiving unit 54 and the analog signal processing unit 44 are provided, two units are provided. Since the phase data is generated by the single digital signal processing unit 56 from the radio waves received by the receivers 10 and 12, the sampling periods can be perfectly matched.

Further, since the first GPS receiver has the conventional digital signal processing section and the control section removed and is provided with the radio signal transmitting section 36 equipped with an antenna instead of these,
The weight and cost can be reduced, and particularly when applied to kinematic surveying in which one GPS receiver is sequentially moved to perform surveying, the effect is extremely effectively exhibited.

[0022]

As described above in detail in the embodiments,
According to the GPS receiver for surveying according to the present invention, the sampling cycle of the phase data is completely matched to improve the precision of surveying, and at the same time, it is possible to achieve both weight reduction and cost reduction.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of a measurement state of a static survey using a surveying GPS receiver according to the present invention.

FIG. 2 is an external view illustrating an example of one receiver of the GPS receiver according to the present invention.

FIG. 3 is a functional block diagram of the GPS receiver shown in FIG.

FIG. 4 is an external view illustrating an example of the other receiver of the GPS receiver according to the present invention.

5 is a functional block diagram of the GPS receiver shown in FIG.

[Explanation of symbols]

 10, 12 GPS receiver 22, 42 GPS antenna 28 Transmission antenna 34 Analog signal processing unit 36 Radio signal transmitting unit 44 Analog signal processing unit 54 Radio signal receiving unit 56 Digital signal processing unit 58 Control unit 60 Memory

Claims (1)

[Claims] 1. Use of at least a pair of GPS receivers that receive radio waves transmitted from a plurality of satellites, the GPS receivers are installed at different points, and the GPS receivers receive the signals at the same time. In a surveying GPS receiver for measuring a distance or a direction between the points based on a phase difference of radio waves, one of the GPS receivers is a GPS antenna for receiving a radio wave transmitted from the satellite, An analog signal processing unit for converting a radio wave received by a GPS antenna into a carrier frequency lower than that of a radio wave emitted from the satellite, and a radio for transmitting a radio signal from a transmission antenna upon receiving an output signal of the analog signal processing unit. A signal transmitting section, and the other of the GPS receivers has a radio signal receiving section having a receiving antenna for receiving the radio signal, and the other of the GPS receivers is transmitted from the satellite. A GPS antenna that receives waves, an analog signal processing unit that frequency-converts and amplifies a radio wave received by the GPS antenna, and a carrier wave phase of a radio wave from output signals of the radio signal receiving unit and the analog signal processing unit. A digital signal processing unit that generates digitized phase data; and a control unit that extracts the phase data sent from the digital signal processing unit at predetermined time intervals and stores it in the storage unit as epoch phase data. The surveying GPS receiver, wherein the digital signal processing unit has a plurality of channels to which the phase data corresponding to the wireless signal receiving unit and the analog signal processing unit are respectively assigned.